Well, first things first I suppose. Get the sump plug off and drain that engine out completely.
Now, the fact that you have been burning oil will be one of 2 things basically. If the oilways are a bit clogged, the pistons coming down into the sump will not be able to shift the oil quick enough, so the oil could have been forced at great pressure passed the oil rings and into the combustion chamber(s).
Alternatively the oil may have been forced passed the crankcase breather system and into the plenum.
So, once oild is drained, I would pop the plenum off. Hopefully this is where the oil has got in. If so, a lot of cleaning and you should be ok. If not, you may be looking at a big problem.
As for MarksDTMCalib, if you don't behave, I will pop around and put diesel in your MV6. Then we'll have that race!!!! Swine.
Anyway, step by step. Hopefully you will be ok.